Phosphorescent phosphor powder, manufacturing method thereof and afterglow fluorescent lamp

Abstract

In an afterglow fluorescent lamp having a structure wherein at least a phosphorescent phosphor layer is set on the internal surface of a glass container, pinholes are prevented from appearing in the layer. The layer is formed, using a phosphorescent phosphor powder, wherein a metal oxide powder whose primary particles have a particle-size distribution with an upper limit particle size smaller than a lower limit particle size of a particle-size distribution that primary particles of a matrix material of the phosphorescent phosphor powder have is mixed, in a ratio by weight that is not less than 10 wt % but not greater than 40 wt %, with the matrix material of the phosphorescent phosphor powder. Therein, the particles of the metal oxide fill the gaps among the particles of the phosphorescent phosphor, and thereby the adhesive strength between the particles of the phosphorescent phosphor is heightened.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a phosphorescent phosphor powder, a manufacturing method thereof and an afterglow fluorescent lamp, and more particularly to prevention of peeling-off of a phosphorescent phosphor layer in an afterglow fluorescent lamp wherein a phosphorescent phosphor is utilized.

[0003] 2. Description of the Related Art

[0004] The afterglow fluorescent lamp makes good use of characteristics (the phosphorescent natures or the long afterglow properties) that the phosphorescent phosphor has, that is, the capabilities to keep glowing persistently for a considerable time after the cessation of the stimulus. Since the lamp remains luminous even after the external power supply is cut off, it is used in the space where a large number of people gather, for instance, a large-sized store, a theater or an underground shopping complex for the general lighting and, at the same time, for the means to indicate the...

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